Ever wonder to have your own electronics lab? Almost every hobbyist fancies having his / her own mini-lab in his home. In this post, we’ll see some of the most important tools you must have in your mini-lab for starting experimentation.
1. Soldering Iron
Tools for electronics
The concept of electronics hobby lab begins with soldering iron itself. Soldering iron is a small welding machine which can melt the soldering metal used for soldering electronic components on a Printed Circuit board. Having a soldering iron with you opens a lot of things for you to experiment with. With a soldering iron at home, you can also quickly solder minor issues in your tv remote or some cut wires in your hobby project or make changes to an existing project. Soldering iron comes in a variety of options, 25Watt, 30Watt, 50Watt and so on. Also, there are a variety of soldering stations which are temperature-controlled and can give you constant temperature all the time, but stations are costly and irons are cheaper. So if you’re a beginner a good quality soldering iron is all you need. (of course with a bundle of solder metal)
2. Common Electronics Components
Why do we setup an electronics lab? To experiment with, right? And what to experiment with if you have no components at all? So the second in this list is having common electronics components at your disposal for creating projects or replacing parts from any existing PCB. Some of the common parts that you must keep in your stock are listed below.
Resistors: Different values from 10-ohm, 39 ohm, 100 ohm, 330 ohm, 470 ohm, 1k, 1.5k, 3.3k, 4.7k, 10k, 33k, 22k, 47k, 100k, 1M, 10M and 100M are few common values to begin with
Capacitors: Capacitors are good for creating power supplies and connecting in number of different circuits, you should have these values in stock, 1nano farad or nF, 10nF, 100 nF, 0.1uF, 1 uF, 10 uF, 47 uF, 100 uF, 470 uF, 1000 uF
Transistors: Both NPN and PNP transistors are good to have in stock like BC548, BC557 as well as some high current transistors like BD139 and MOSFETs like Z44
Diodes: useful for making power supplies and electronics switches, you should have at least one type of rectifier diode and one switching diode and few Zener diodes, Values are 1N4001 and 4148 to name a couple
3. Zero PCBs or General Purpose PCB
Zero PCb
This is a general purpose PCB on which you can mount your components and make circuit connections. Ideally suited for creating a complete test circuit. Unlike printed circuit board, this PCB does not have any thing printed on it and hence there are no interconnections. Instead, it has number of different individual holes NOT connected to any other hole, so you can make the interconnects by simply using some long wires of sufficient length
4. Breadboard
breadboard for your hobby electronics lab
Making circuits on a board requires lots of time and special skills. For a long time, scientists and engineers rely on a simple method to develop any circuit. In this technique, circuit is built on something called breadboard!!! Confused? Actually, a breadboard is a rectangular board which is having lots of HOLES to place electronic components in it. The holes in a breadboard are interconnected in such a manner that makes the connection of components easier. Still, for making additional connections, we need simple single strand wire. This is the wire which has only one thick thread inside the insulation. To know about details of how to use a breadboard, you can refer to this article here
5. Connecting wires
Connecting Wires
These are used for interconnecting components on zero PCB or making connections on a breadboard or for simply having things connected with each other without soldering. Connecting wires in all formats should be present in small quantity, format means: Single stand wire, multistrand wire, M-M connectors, and F-F connectors
6. Digital Multimeter
Digital Multimeter for your electronics lab
Digital Multimeter is one of the most essential tools an electronics hobbyist should own. While developing electronics circuits, we come across lots of different parameters which needs to be checked, for example, voltage, current, resistance, continuity etc… there are separate instruments available for each of these parameters, and multimeter is the one instrument having facility for doing all above measurement. There are analog and digital multimeters available. But digital are becoming more common these days and hence we use digital multimeters, which is also referred as DMM. Now and onwards, we use simply multimeter for referring to a DMM. It’s basically a measuring instrument which can measure.
To learn in detail about how to use a digital multimeter, you can refer the tutorial here
7. Wire Cutter / Stripper
wire stripper a must-have tool for the electronics lab
Lastly a wire cutter and a stripper will help you cutting the leads on pcb’s and cutting your wires in desired length. This mechanical tool is one of the very important tools you should have in your arsenal
8. Batteries / Power Supply
battery or power for electronics lab
For quickly prototyping with electronics circuits, couple of 1.5 and 9v batteries are must have in the stock. They help us in powering number of different circuits and testing them out as and when required. If you don’t have batteries, at least have a wall adapter giving out a standard 12v DC voltage. What we need is a dc power source no matter how it comes from either batteries or adapter. And for those who do lot of works on breadboard, having a breadboard power supply is also a good thing. If you want to create your own power supply, follow this tutorial here
On our courses page, you can see lots of interesting online courses for more deeper understanding of technologies here
All circuits and gadgets and everything that is running on Electrical energy requires some particular Voltage and Current. There are 2 type of electrical powers available, called AC Supply and DC Supply. AC Supply is the one which is available to us from our Home Socket, this is a very high voltage (230v) and coming directly from the power plant, no storage. While in India, and in most of the countries, the domestic supply is AC only, most of the electronics circuits (almost all of them!!!) runs only on Pure DC power supply. Now DC is Direct Current and AC is alternating Current, below image might clear some things for you
above image shows that DC is a continuously ON and constant value whereas AC is continuously varying and changing its value continuously. Electronics circuits require no more than 12v DC and in most cases not more than 5v DC, such small DC voltages are not hazardous to human being and you can touch the source of such small DC supply, but never attempt to touch AC supply at all. Now let’s see how this AC is converted to DC for our use.
All electronics circuits run on DC Power supply and understanding the working of the power supply is the main key for running your project. A poor power supply may interfere in lots of different things making the circuit to not work, to hang sometimes, or to fluctuate the proper working. Hence though it’s little boring to study, its always good to understand what are the DC Power supplies, and what are the sources of good DC power
DC Adapters
Using a very simple and popular electronic component called diode, any AC signal can be converted to DC signal. But before doing this, we have to drop down the 230v AC to somewhat smaller voltage like 12V AC. This is done by using a Step-Down Transformer. Step Down Transformer is an AC to AC Converter which can convert a higher AC voltage to smaller AC voltage. After Step Down transformer, a diode-based rectifier circuit is used to convert the AC supply to DC Supply.
A Typical transformer looks like this
It has 2 coils, one called the primary winding and the other called secondary winding. For a typical step-down transformer, Primary is the One where we connect the Mains Supply (230v) and secondary is the one where we observe step down voltage(say 12v). You can develop such a small circuit on your own using a circuit like below. After a diode-based rectifier, we’re required to use a Capacitor filter and voltage regulator. A Voltage Regulator like 7805 can give you 5 v of regulated constant DC voltage at the output. There are many variants of voltage regulators like 7805,7809, 7812 and so on. Below is a simple DC power supply-Circuit
dc power supply
Above circuit shows a transformer, a bridge rectifier which converts the AC output from the transformer to DC pulsating voltage. The capacitor is used to filter out the AC component of the supply. And 7805 is the voltage regulator used whose job is to regulate the voltage to +5v constant supply. A small 100nF output capacitor ensures the high-frequency noise being conducted to Ground
LED’s are perhaps the most interesting electronic component that we use in circuit. LED’s are (Light Emitting Diode) components which can emit a specific light. It can be RED, Green, Blue or Yellow. LED’s require very less voltage to turn ON (typically 3v) and they have a very long life. We see LED’s in power indicators in almost any electronic appliance. The power light we see on TV, DVD, microwave, in TV remote control are all LED’s. We have LED TV’s now a day’s which uses LED’s to give the backlighting to the LCD Panel in it
Symbol of LED
LED’s are directional devices and are required to be connected in a specified direction only in a circuit. The LED’s are having two leads, they are called as Anode, and Cathode as shown in below image
The above image shows the LED circuit symbol in the upper side and how to identify the leads of LED in the lower side.
LED Usage
The most important thing to remember about using LED in any electronic circuits, is that never, I mean never ever connect LED to any Power Source directly. LED’s are to be always connected to any power source with a series resistor.
LED and Resistor
LED Series Resistor
There is a little Mathematics here about what should be the idle value of series resistor with LED. To be frank, there is no honest “value” or any real value. All the LED’s have a specified maximum current specified by the manufacturer which should not be exceeded, that’s it. We can use any resistor which limits the current flowing through resistor less than a specified value. As a thumb rule, all common LED’s have a rating of maximum of 60mA (mili amperes) It means, we should not allow more than 60 mA of current to pass through LED otherwise it will get damaged.
Using the simplest Ohms Law, we have this
R = V / I
Where
R = Resistance
V = Voltage Applied
I = current passing through the circuit
So if we want to limit current to a known value, we have to put the known voltage (which we apply, say 9v as our battery voltage) and the known Current in this equation to get resistor value.
For the sake, we’ll assume we are working on 9v, and we wish to limit our current to 20 mA
So
R = V / I
Hence,
R = 9v / 20mA
R = 9v / 0.02 Ampere
R = 450 ohm
As 450ohm is not a standard value, we can choose any value close to it, for example, we can use 470 Ohm or even 680 Ohm.
Remember, the LEDs in a most electronic circuits are used only for the purpose of Indication and not to light up a room. So we must use the resistor value as large as possible on which LED is lit, so as to keep our overall current consumption limited.
Every electronic circuit, project or gadget like our mobile phone or the speakers that we use, require electrical power to function. We can draw this required electrical power from our mains outlet using a power supply. When we want mobility and freedom from wires, we have to use a portable powerhouse. These are DC power sources and we call it a Battery. There are many types of batteries and there are literally infinite appliances that use batteries of different types. Our TV remote, Wall-Clock, wristwatches, cars, laptops, mobile batteries are everywhere. The battery provides a mobile voltage source. Depending upon our requirement we chose a battery which fits our requirement and our budget. e-vidya comes with a 9V Battery which is available everywhere and most easy to use. The household battery which we also call as pencil cell used in tv remote is a small one and gives 1.5V of DC voltage. The DC power source is denoted in the circuit diagram by a special symbol as shown below
Anode represents the positive terminal of battery and cathode represents the negative terminal of the battery. During building various circuits, we have to take extreme precaution that we should not connect it wrong otherwise; it may cause severe problems to our circuit. So take care while connecting the battery to any circuit. The 9v Battery provided has a clip showing red wire for an anode and black wire for a cathode. 9v battery looks like this
9 Volt Batteries
How Battery Works?
So what actually is a Battery? It is a combination of two or more electrochemical cells in which stored chemical energy is converted into electrical energy. Each cell consists of two half cells connected in series through an electrolytic solution. One-half cell houses the Anode to which the positive ions migrate from the Electrolyte and the other houses the Cathode to which the negative ones drift. The two cells are may be connected via a specific structure allowing ions (charged particles) to flow.
Types of Batteries
Apart from these 9v Batteries, below are some common types of batteries we use along with pictures and their rated voltage and applications where they are used
Making circuits on a board requires lots of time and special skills. For long time, scientists and engineers rely on a simple method to develop any circuit. In this technique, circuit is built on something called breadboard!!! Confused? Actually a bread board is a rectangular board which is having lots of HOLES to place electronic components in it. The holes in bread board are interconnected in such a manner that makes connection of components easier. Still for making additional connections, we need simple single strand wire. This is the wire which has only one thick thread inside the insulation. Look below pictures for knowing about bread board and making a simple LED circuit on breadboard
It has ten rows (lines) of holes in the main area. Each line has 64 holes. There are also two power lines at the top and two at the bottom.
Bare Breadboard
As you can see in above image. The bread board is basically a rectangular box, made up of plastic material. The breadboard, as shown in the above picture is having lots of holes which can house components inside it. All we have to do is understand the internal connections of breadboard and insert components into it.
The internal structure of breadboard is also very simple. As in there are lots of holes to the breadboard, there must be something which interconnect the components. If we consider the above picture; we can see there are columns of 5 Holes each and there are Rows of 5 Holes each. The rows are spared in the top of breadboard and the bottom of breadboard. The columns occupy the entire middle area of breadboard. The columns are interconnected vertically, and the rows are interconnected horizontally. See below picture for reference
Vertical Connection
As you can see in above picture, the red vertical line shows the interconnection of holes present in one Top column and one in bottom column. There is a break as shown in the picture. So the vertical column is only connected to five points in one column and does not connect with the to the other column down the break.
Similarly, the rows are also interconnected as shown in below picture
Horizontal Connections
There is a break in row connections also. Also the rows are connected in straight horizontal line as shown by red color in above image so these points don’t intersect with the line parallel to it. So we can use these lines for Supply and GND both on the top of breadboard as well as at the power of breadboard. Hence they are also called as power rails or power lines of breadboard.
Using Breadboard
Now using this interconnected board of holes arranged in rows and columns, we have to construct a real circuit. You can insert any component having leads in breadboard just like the resistor is inserted in below figure.
Inserting Component
Make sure that the resistors both leads are inserted in 2 different columns and not in the same column. If a component is inserted in same column, it will get shorted.
To make interconnections on Breadboard among components we use a special type of wire. This is called single strand wire. It’s the wire which is having only single core or single thread which is thick enough to get inserted in breadboard. Look below picture.
Inserting Jumpers
We’ve to cut the wire in required size and strip the both ends of wire to make it easier to get inserted into a breadboard. This wire can be used to connect one lead of a component to the other component forming a circuit. Similarly we can construct entire circuit of components on breadboard and interconnections with these types of wires.
Interconnect Of Component
In above picture, you can see, the two resistors leads are connected using this single strand wire. You can use the horizontal power rails to insert the leads of component which are either going to supply voltage vcc or the ground terminal. In above circuit, we’ve connected LED to the horizontal power line. Take a close look over LED in below picture.
Interconnect Of Component
IC’s with bread board
Inserting and using electronic components is fairly easy, now we’ll see how to use IC’s on breadboard.
As you can see the first picture, there is a break in the 2 vertical columns of breadboard. This break is there to facilitate the use of IC’s on breadboard, carefully, we can insert IC’s of any size into the breadboard using this break rail without shorting any of its pins.
Inserting IC
Above picture shows how IC is connected. Now as you see, we have 5 holes in one column, and after inserting IC, we have 4 holes vacant for every IC pin to make interconnections. We can insert wire anywhere from these four points to get a connection with that particular pin of IC
Now below image shows how a small circuit can be built
IC Connection
From above two images it’s clear that there are plenty of pins available for wiring and interconnections with Integrated circuit.
Make sure you insert all the components properly and give the power correctly. Below shows a complete image with all the required components and power. This image is animated.
A Light Dependent Resistor (LDR) is also called a photoresistor. The passive component is basically a resistor whose resistance value increases when the intensity of light decreases.
The resistor behaves depending upon the amount of light falling on it. In general, LDR resistance is minimum (ideally zero) when it receives a maximum amount of light and goes to maximum (ideally infinite) when there is no light falling on it. The resistance is very high in the darkness, almost high as 1MΩ but when there is light that falls on the LDR, the resistance is falling down to a few KΩ.
The vast majority of LDRs are made from cadmium-sulfide (CdS), and they are very cheap. They are very good at detecting changes in light levels and determining if it is ‘dark’ or ‘light’.
Light Detecting Sensor
Light-dependent resistors come in different shapes and colors. LDRs are very useful in many electronic circuits, especially in alarms, switching devices, clocks, street lights and more. There are some audio application uses such as audio limiters or compressors. It is used to turn ON or OFF a device according to the ambient light.
How LDR Works
LDR has two wire leads that are connected to a face of the light detector. See the image above, the two metal dots we see are the ends of those 2 electrodes. The main body of the light detector component is made up of ceramic material which is an excellent insulator. On the face of the ceramic, a thin strip of cadmium sulphide is coated in a zig-zag pattern (to maximize the length of the strip while keeping the component small) which is connected at each end to an electrode. The front face is then coated in clear plastic, epoxy, glass, or similar material.
Cadmium-sulphide is a high resistance semiconductor and is chosen for light detectors as it gives the same spectral response as the human eye. It means cadmium-sulphide can ‘sees’ the same range of wavelengths of light that we humans can see. And it reacts to the light by increasing/decreasing the conductivity. Specifically, cadmium-sulphide is a photoconductive material. That means that photons of light hitting it with sufficient energy will release electrons from their atomic bonds resulting in providing higher conduction or lower conduction. When a negatively charged electron is freed by a photon of light, it leaves behind a positively charged ‘hole’. When a voltage is applied across the two-wire leads of the light detector, the free electron moves one way along the CdS strip, and the free ‘hole’ moves the other way; and it is this movement of charge which is electricity flowing through the light detector. The higher the light intensity, the more photons of light are hitting the CdS strip, the more electron-hole pairs are generated, the more electricity can flow through the light detector, and so the lower the resistance of the light detector. It is easier for electricity to flow through the light detector when the light intensity hitting it is high.
Electrically, it results in the increased or decreased resistance offered by the LDR.
